Rugged, removable, electronic device

ABSTRACT

An apparatus is disclosed, including a rugged electrical connector supporting an external bus protocol including a power signal; a backshell canister mated to the electrical connector; an active electronic component housed in the canister; and an electrical connection between the active electronic component and the rugged electrical connector.

This application is a continuation in part of co-pending U.S.application Ser. No. 10/951,155, entitled “Rugged, Removable, ElectronicDevice”, filed Sep. 28, 2004, in the name of the inventor Vonn A. Zauberand commonly assigned herewith.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention pertains to electronic devices for use in harsh,demanding environments.

2. Description of the Related Art

The application of computing technology continues to expand into everharsher environments. At one time, computers and other computing deviceswere housed in separate, dedicated, climate controlled rooms. Peoplewishing to use such machines would go to where they were located tointeract with them. Considerable effort was made to cater to theenvironmental needs of the machines, even to the point ofinconveniencing the users. Accordingly, not much concern was given todesigning computers and computing devices to withstand the rigors ofharsh environments.

Increasing demands on computing technology have changed all that. Today,computing devices are being deployed in ever harsher environments withone or more conditions such as extreme temperatures, high shock, highvibration, excessive humidity, and chemical exposure. For instance,computers are commonly found in oilfield applications where they aresubjected to extremes of temperature, shock and vibration'. Computingtechnology has also found growing application in military applications,including weapons systems that are particularly high performance.Military applications, as well as some civilian applications, also addthe additional pressure of life and death stakes as a function ofperformance level.

Much effort has therefore gone into “ruggedizing” computing technology.Sometimes this results in changes to the designs of the computingdevices, connectors, buses, storage devices, etc. For instance, thedesign of a microprocessor might be changed to enable to withstandhigher or lower temperatures found in a particular harsh environment.Sometimes the effort results in techniques for installing an existingdesign. For example, an existing microprocessor might be mounted in away that helps isolate it from vibration. Cumulatively, these kinds ofchanges significantly impact the performance of computing technology indemanding environments.

One complicating factor is the reality that ruggedization is but onefactor in the design of a computing apparatus. The engineering taskusually involves a multitude of tradeoffs among competing considerationsthat will be implementation specific. Thus, a particular ruggedizationtechnique may not be acceptable if it results in excessive size andweight for, e.g., a missile whereas it may be acceptable if used in,e.g., an armored ground vehicle. Thus, it is not enough that aparticular ruggedization technique is available and will work, it mustalso not force unacceptable tradeoffs with other engineeringconstraints. Preferably, the ruggedization technique will actuallyfacilitate or enhance the design's ability to meet other engineeringconstraints. However, even if it facilitates the design effort inmultiple areas, it may still be unacceptable if it undesirably impactsthe computational performance of computing apparatus.

Another complicating factor is that the computing apparatus as a wholemust be ruggedized. It does little good to ruggedize the computingdevice (e.g., the processor or controller) if the storage is not.Storage is equally important in the performance of a computing apparatussince the computing device is dependent upon the storage for, amongother things, the data on which it operates. This becomes more importantas computing technologies are applied to more computationally intensiveproblems that process higher volumes of data that require greaterstorage. Furthermore, the electrical connection between the computingdevice and the storage is dependent upon the buses and connectorsthrough which the electrical connection is made. The ruggedization ofeach of these aspects of the computing apparatus involves differentconsiderations such that techniques applicable to, for example, thecomputing device, may not be applicable to, for instance, theconnectors.

To illustrate the difficulties of balancing these factors, consider therelatively recent development of removable mass storage. To facilitateportability, the mass storage device should be small and lightweight. Tofacilitate interoperability, the mass storage device should berelatively platform independent, i.e., to be usable with a variety ofplatforms. It should provide stable connections, high numbers ofaccesses, and fast accesses. For present purposes, it should be able towithstand extremes of temperature, high shock, high vibration, and highhumidity. It should also cost relatively little.

Some “ruggedized” Universal Serial Bus (“USB”) flash drive, removablemass storage devices have been developed. These solutions are typicallysufficiently small, light, and platform independent. Some have hardenedpackages for increased durability and, presumably, better tolerance forshock. However, they also employ the standard USB connector andinterface. The standard USB interface is not suitable for militaryapplications and for most harsh environments. Among other problems, theconnectors are fragile and the connections they make are susceptible tofailure in the face of high vibration and/or shock.

Some military solutions have been developed to address the deficienciesof these ruggedized USB flash drives. These solutions admirably addressthose deficiencies and are typically built on a removable flash card,such as a Compact Flash, Personal Computer Memory Card InternationalAssociation (“PCMCIA”), etc. card. They generally include a host chassiswith a removable cartridge assembly. However, they usually include aheavy internal power supply. They also tend to be bulky, large,expensive, and platform dependent.

The present invention is directed to resolving, or at least reducing,one or all of the problems mentioned above.

SUMMARY OF THE INVENTION

The invention includes an apparatus, comprising: a rugged electricalconnector supporting an external bus protocol including a power signal;a backshell canister mated to the electrical connector; an activeelectronic component housed in the canister; and an electricalconnection between the active electronic component and the ruggedelectrical connector.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention may be understood by reference to the followingdescription taken in conjunction with the accompanying drawings, inwhich like reference numerals identify like elements, and in which:

FIG. 1 is an assembled, perspective view of one particular embodiment ofthe present invention;

FIG. 2 is a partially sectioned, plan view of the embodiment in FIG. 1;

FIG. 3 is an exploded, perspective view of the embodiment of FIG. 1;

FIG. 4 is a partially disassembled, perspective view of a secondembodiment in accordance with the present invention; and

FIG. 5A–FIG. 5B illustrate one particular embodiment of the presentinvention.

While the invention is susceptible to various modifications andalternative forms, the drawings illustrate specific embodiments hereindescribed in detail by way of example. It should be understood, however,that the description herein of specific embodiments is not intended tolimit the invention to the particular forms disclosed, but on thecontrary, the intention is to cover all modifications, equivalents, andalternatives falling within the spirit and scope of the invention asdefined by the appended claims.

DETAILED DESCRIPTION OF THE INVENTION

Illustrative embodiments of the invention are described below. In theinterest of clarity, not all features of an actual implementation aredescribed in this specification. It will of course be appreciated thatin the development of any such actual embodiment, numerousimplementation-specific decisions must be made to achieve thedevelopers' specific goals, such as compliance with system-related andbusiness-related constraints, which will vary from one implementation toanother. Moreover, it will be appreciated that such a developmenteffort, even if complex and time-consuming, would be a routineundertaking for those of ordinary skill in the art having the benefit ofthis disclosure.

Turning now to the drawings, FIG. 1–FIG. 3 illustrate a first embodimentof a removable electronic apparatus 100 constructed in accordance withthe present invention. The electronic apparatus 100 comprises a ruggedelectrical connector 103 supporting an external bus protocol including apower signal. A backshell canister 106 is mated to the rugged electricalconnector 103. An active electronic component 109 electrically connectedto the rugged electrical connector 103 is then housed in the backshellcanister 106.

The rugged electrical connector 103 is sufficiently rugged to withstandelevated levels of shock, vibration, impact, etc. and consequently beresistant to damage by crushing, deformation, breakage, disassembly fromvibration, etc., found in harsh, demanding environments. To some degree,the level of ruggedness will be implementation specific. Differentlevels of shock and vibration will be found, for instance, on the deckof drilling rig in hydrocarbon exploration and production than will befound on the floor of a machine shop. However, various militaryorganizations routinely specify standards with respect to these kinds ofconditions that are referred to as a “military specification,” or “milspec”, and mil specs can be referred to where applicable, even incivilian contexts, although compliance with mil specs is not necessaryto the practice of the invention. For instance, standards are also set bthe American Society of Testing and Materials (“ASTM”).

In the illustrated embodiment, the rugged electrical connector 103 is acylindrical connector, and, more particularly, a circular connector.Suitable circular connectors are commercially available off the shelffrom a number of vendors, such as Amphenol Aerospace, a division of:

-   -   Amphenol Corporation    -   358 Hall Avenue    -   Wallingford, Conn. 06492    -   USA    -   ph: (877) 267-4366    -   ph: (203) 265-8900    -   fax: (203) 265-8516    -   e-mail: aphinfo@amphenol.com    -   or, alternatively:    -   Glenair, Inc.    -   1211 Air Way    -   Glendale, Calif. 91201    -   USA    -   ph: (818) 247-6000    -   fax: (818) 500-9912

In general, circular connectors come in a bayonet-style or athreaded-style, and the illustrated embodiment is a bayonet-stylecircular connector. Thus, the apertures 113 (only one shown) that matewith ears (not shown) on the mating connector 117, shown in FIG. 1 inghosted lines.

Other types of connectors might be employed in alternative embodiments.

The rugged electrical connector 103 of the illustrated embodiment alsopossesses a number of characteristics that, while not necessary to thepractice of the invention, may be desirable in some embodiments. Forinstance, the rugged electrical connector 103 is environmentallyresistant, e.g., waterproof, not susceptible to shock or vibration, etc.The rugged electrical connector 103 is also self-aligning, scoop-proof,and keyed. This particular embodiment furthermore is constructed tocomply with the MIL Standard MS27467 (MIL-DTL 38999, Series I),promulgated by the United States Armed Forces. However, compliance withnumerous other MIL standards and industrial standards may also besuitable in alternative embodiments.

As noted above, the cylindrical electrical connector supports anexternal bus protocol including a power signal. Exemplary external busprotocols include, but are not limited to, the Universal Serial Bus(“USB”) protocol and the IEEE 1394 protocol (e.g., FireWire, etc.).

External bus protocols specify a number of characteristics, bothphysical and electrical, that a bus must meet to be compliant therewith.Note that the term “external bus protocol” is used as in the computingarts, e.g., to mean a bus that connects a computing device to aperipheral device. Note also that the USB and IEEE 1394 protocols areopen standards, meaning they are available to the public. They have alsoachieved a wide acceptance such that their use in the present inventionmakes the apparatus 100 compatible with a wide array and number ofcomputing devices.

The backshell canister 106 of the illustrated embodiment is alsocommercially available off the shelf, and typically from the same vendorfrom which the connector 103 is obtained. The backshell canister 106 inthe illustrated embodiment is, like the rugged electrical connector 103,environmentally resistant. This particular embodiment furthermore isconstructed to comply with the MIL Standard MS27467 (MIL-DTL-38999,Series I), promulgated by the United States Armed Forces. However,compliance with numerous other MIL standards and industrial standardsmay also be suitable in alternative embodiments.

The backshell canister 106 and the rugged electrical connector 103 arejoined through a threaded connection 112, best shown in FIG. 2. As isshown best in FIG. 3, the rugged electrical connector 103 includes amale thread 300 on the outer circumference of a drum 303. The backshellcanister 106 includes a female thread 306 on the inner circumference ofa rotating ring 309 at the open end 312 of the backshell canister 106.The threaded connection 112 is formed by rotating one of the ruggedelectrical connector 103 and the backshell canister 106 is relative tothe other in conventional fashion. In the illustrated embodiment, therotating ring 309 is rotated onto the drum 303 to make the threadedconnection 112. The outer surface of the rotating ring 309 is knurled orscored to improve the user's grip and thereby facilitate this function.The threaded connection 112 compresses an O-ring 315 between a shoulder200 and an end of drum 303, best shown in FIG. 2, to make the threadedconnection 112 watertight and airtight.

In various embodiments, the backshell canister 106 and/or outer portionsof the electrical connector 103 may comprise materials such as aluminum,an aluminum alloy, a stainless steel, or the like and may be coated(e.g. anodized, etc) to inhibit corrosion and wear. Alternatively, thebackshell canister 106 (or portions thereof) may comprise one or more ofa radiopaque material, a translucent material, and a transparentmaterial to facilitate communication between the active electroniccomponent 109 and a computing device (not shown), as will be discussedin more detail below. The materials will be implementation specific andstill other types of materials may be used in alternative embodiments.

The electronic component 109 is, in the illustrated embodiment,electrically connected to the rugged electrical connector 103 by aplurality of leads 115. The number of leads 115 will be a function ofthe external bus protocol supported by the electronic apparatus 100.Note that the electrical connection between the electronic component 109may be implemented using techniques other than the leads 115. Forinstance, other embodiments might employ pins or finger edge connectors(e.g., gold-plated finger edge connectors), depending on theimplementation of the active electronic component 109 and the ruggedelectrical connector 103.

In one particular embodiment, a rigid flex harness (not shown) is usedto implement the electrical connection between the rugged electricalconnector 103 and the active electronic component 109. A rigid flexharness permits control over impedances and have repeatability in termsof assembly. Two of protocols suitable for use in the present invention,USB 2.0 and Firewire, have high data rate potential and signal integritycan be tightly maintained by designing a rigid flex harness to pick upthe back of the rugged electrical connector 103 and mate with whateverelectronic assembly (i.e., the active electronic component 109) isinside the backshell canister 106.

The electronic component 109 is an active, as opposed to passive,electronic device. In the illustrated embodiment, the electroniccomponent 109 is a memory device. In the illustrated embodiment, thememory device is commercially available off the shelf in the form of aUSB flash drive. The electronic component 109 may be obtained bystripping away the shell and connector of a commercially available USBflash drive, leaving only the memory device that is then assembled intothe present invention. Alternatively, the electronic device 109 may beobtained without the shell and connector, then assembled into thepresent invention.

However, the invention is not limited to memory devices or even a singleelectronic device. Furthermore, as is shown in FIG. 4, alternativeembodiments may employ a second electronic component 400 that may or maynot be the same as the electronic component 109.

Thus, the active electronic component 109 may, in some embodiments,actually constitute and) 30 assembly of multiple electronic devices, atleast one of which is an active.

The electronic component 109 can be, in some embodiments, a wirelesslytransmitter, receiver, or transceiver permitting a wireless link betweenthe apparatus (not shown) to which the apparatus 100 is too be connectedand a remote location. For instance, the apparatus 100 may be equippedwith a small antenna (not shown) and the backshell canister 106 made ofsome non-metallic material. In this way, a via an USB interface, a fielddevice (such as a data logger) can establish a wireless Ethernet link toa field engineer with a commercial laptop, etc. Alternatively, an IrDA(“Infrared Data Association”) standard connection, which is the standardthat PDAs (“Personal Digital Assistants”), notebook computers, printers,etc. use to wirelessly link up, may be employed.

The backshell canister 106 in such embodiments may be constructed from ametal material provided an IR (“Infrared”) window is provided; or, thewhole backshell canister 106 may be made of an IR transparent material.For instance, Germanium (Ge) is commonly used for lenses and windows inIR systems operating in the 2–12 tm range and would be suitable for thisapplication. The operational environment will not be problematicalbecause Germanium is inert, mechanically rugged, and fairly hard. It isan excellent choice for multi-spectral systems and for applicationswhere electromagnetic interference (“EMI”) shielding is necessary.Germanium can also be electrically heated for anti-fogging or anti-icingapplications.

The electronic component 109 is stabilized within the backshell canister106 by a potting material 315, best shown in FIG. 3. The pottingmaterial 315 is, by way of example and illustration, but one means forstabilizing the electronic component 109. Other means may include, forinstance, expanded foam or a brace. Some embodiments may omit means forstabilizing the electronic device altogether. When used, the choice ofstabilizing means will be implementation specific. For instance, in theillustrated embodiment, the potting material 315 is selected to helptransfer heat generated by the electronic component 109 is transferredaway from the electronic component 109. However, in some harshenvironments with extreme temperatures, this may be undesirable. Also,weight and size constraints may impact the choice of stabilizing means.Still other considerations may come into play in some embodiments.

In one particular embodiment, the removable electronic apparatus 100 isa “removable memory unit” meeting the requirements of both the milstandard MS27467 and the USB 2.0 standard. This particular embodimentprovides a rugged memory unit offering USB 2.0 performance for theHIMARS Universal Launcher Interface Unit (“HULIU”) of the M142 Launcherfor the High Mobility Artillery Rocket System (“HIMARS”) of the UnitedStates Military. Selected characteristics of this particular embodimentare set forth in Table 1.

TABLE 1 Selected Characteristics Characteristic Parameter MemoryCapacity 1 Gigabyte, other capacities possible Read/Write Performance 20Mbyte/sec Read, 10 Mbyte/sec Write Operating Temperature −40 C.–+85 C.High Reliability 5,000,000 write/erase cycles

Turning now to FIG. 5A, the electronic component 109′ is an electronicassembly and is potted in an encapsulating material (not shown) CytecEN-12. The Cytec EN-12 is a two-component, highly flexible liquidpolyurethane molding and encapsulating systems commercially availableunder the mark CONATHANE® EN-12 from:

-   -   Cytec Industries Inc.    -   5 Garret Mountain Plaza    -   West Paterson, N.J. 07424    -   E-mail: INFO@CYTEC.COM    -   Phone: 973-357-3100.        Additional information is available from        <http://www.conap.com/index.cfm?page=ElectList>. This particular        material is submersion related and exhibits excellent shock        absorption.

The connector 103′ is a M27467T11B35P (MIL-C-38999 Series I) connectorcommercially available from ITT Cannon, among others. The connector 103′employ four pins 500–503, shown best in FIG. 5B, for foursignals—namely, USB +5 V DC, USB 5 V Return, USB DP, and USB DN. Notethat the signals are defined by the USB 2.0 standard, which is widelyknown and readily available from many sources. Table 2 contains a pinoutfor the connector 103′ in this particular embodiment. Note, however,that alternative pinouts may be employed. The pins themselves are “22D”pins (also known as M39029/58-360 pins, or by their SAE designationAS39029/360), and may be implemented with Cannon P/N 030-2042-026(Special) Short Contact Pins, as are commercially available. Note thatthe two pins 501, 502 are modified as described below.

TABLE 2 Pinout Pin # Connection 1 N/C 2 USB +5 V DC 3 USB DP 4 USB DN 5USB 5 V Return 6 N/C 7 N/C 8 N/C 9 N/C 10 N/C 11 N/C 12 N/C 13 N/C

The connections between the pins 500, 503 carrying the USB +5 V DC andUSB 5 V Return signals and the electronic component 109′ can be madeusing any suitable technique. The connections between the electronicdevice 109′ and the pins 501, 502 carrying the USB DP and USB DN signalsare made by controlled impedance twisted pair cable 510. The twistedpair cable 510 comprises a 1031–216B cable partially encased inM23053/5-104 heat shrink sleeving (approximately 4–5 mm wide)approximately 15 mm from each end of the wire 511, 512 in a manner notshown. The 1031–216B cable is commercially and readily available fromThermax CDT. Further information may be obtained from<http://www.thermaxcdt.com/contact_us.asp>.

More particularly, the USB 2.0 standard specifies that power connectionsbe established before and broken after the data connections. Most USB2.0 connections achieve this by having electrical contacts of varyinglengths, with the data contacts being shorter than the power contacts.This particular embodiment of the present invention mechanicallyemulates this structure by shortening the pins 501, 502 for the USB DPand USB DN connections so that they are shorter than the pins 500, 503for the USB +5 V DC and USB 5 V Return connection. Thus, unlikeconventional electrical connectors of this type, the connector 103′ willestablish power connections before and break power connections after thedata connections. In the illustrated embodiment, the length L₁ for thepins 500, 503 is 8.81 mm and the length L₂ for the pins 501, 502 is 7.61mm.

Furthermore, the twisted pair cable 510 connection between the datasignal pins 500–503 and the electronic component 109′ is designed with acontrolled impedance that matches that of the USB transmitter/receiverto minimize “reflections” which interfere with high data rate transfers.The USB 2.0 standard permits the detection of error rates, to which suchreflections contribute, so that transmission rates can be slowed. Thus,the twisted pair cable 510 is designed to cabling to minimize thechances of impedance mismatches which would result in performancedegradation. The impedance is determined by a number of implementationspecific factors, such as the number of twists per inch and the numberof strands in the wires of the cable. The twisted pair cable 510therefore emulates the electrical performance of conventional USBcabling through its design and implementation.

As mentioned above, the component 109′ is an electronic assemblyincluding an electronics board 512, a USB controller 513, and a memorydevice 514. The subassembly comprised of the electronics board 512, USBcontroller 513, and memory device 514 is affixed to a circular blank 516by a physical mount 518. The circular blank 516 is sized to fit with thebackshell canister 106, not shown in FIG. 5A–FIG. 5B, and stabilizes thecomponent 109′ within the backshell canister 106 during assembly untilthe encapsulating material is inserted. The electronic assembly alsoincludes a header board 520 that permits electrical contact between thewires of the electrical connection 115′ and the subassembly of theelectronics board 512, USB controller 513, and memory device 514.

Thus, in this particular embodiment, the invention provides anindustrialized/militarized USB solid-state, mass storage drive. Theunique packaging and component choice make it the only USB drive capableof surviving military or harsh environment extremes, includingtemperature, shock, vibration, submersion, EMI, and nuclear. It does allthis while retaining the “hot pluggable” feature of standard USBdevices, without the fragility of a typical USB Type A connector.

This concludes the detailed description. The particular embodimentsdisclosed above are illustrative only, as the invention may be modifiedand practiced in different but equivalent manners apparent to thoseskilled in the art having the benefit of the teachings herein.Furthermore, no limitations are intended to the details of constructionor design herein shown, other than as described in the claims below. Itis therefore evident that the particular embodiments disclosed above maybe altered or modified and all such variations are considered within thescope and spirit of the invention. Accordingly, the protection soughtherein is as set forth in the claims below.

1. An apparatus, comprising: a rugged electrical connector supporting anUniversal Serial Bus external bus protocol including a plurality ofpower signals and a plurality of data signals and including a pluralityof pins mechanically emulating a plurality of Universal Serial Buscontacts; a backshell canister mated to the electrical connector; amemory device housed in the canister; and an electrical connectionbetween the memory device and the rugged electrical connector.
 2. Theapparatus of claim 1, wherein the rugged electrical connector comprisesa cylindrical electrical connector.
 3. The apparatus of claim 1, whereinthe rugged electrical connector is at least one of self aligning, keyed,and scoop-proof.
 4. The apparatus of claim 1, further comprising meansfor stabilizing the memory device in the backshell canister.
 5. Anapparatus, comprising: a rugged electrical connector supporting anexternal bus protocol including a power signal; a backshell canistermated to the electrical connector; a memory device housed in thecanister; and an electrical connection between the active electroniccomponent and the rugged electrical connector, the electrical connectionincluding a twisted pair cable emulating the electrical performance ofan Universal Serial Bus cable for the transmission of data.
 6. Theapparatus of claim 5, wherein at least one of the rugged electricalconnector and the backshell canister is environmentally resistant. 7.The apparatus of claim 5, wherein the rugged electrical connector is atleast one of self aligning, keyed, and scoop-proof.
 8. The apparatus ofclaim 5, wherein the external bus protocol comprises an open standardprotocol.
 9. The apparatus of claim 5, further comprising means forstabilizing the active electronic component in the backshell canister.10. An apparatus, comprising: a rugged electrical connector supportingan external bus protocol including a power signal, the connectorincluding pins mechanically emulating Universal Serial Bus contacts; abackshell canister mated to the electrical connector; a memory devicehoused in the canister; and an electrical connection between the activeelectronic component and the rugged electrical connector.
 11. Theapparatus of claim 10, wherein at least one of the rugged electricalconnector and the backshell canister is environmentally resistant. 12.The apparatus of claim 10, wherein the rugged electrical connector is atleast one of self aligning, keyed, and scoop-proof.
 13. The apparatus ofclaim 10, wherein the external bus protocol comprises an open standardprotocol.
 14. The apparatus of claim 10, further comprising means forstabilizing the active electronic component in the backshell canister.15. A removable mass storage device, comprising: a circular ruggedelectrical connector supporting an external bus protocol including apower signal; a backshell canister mated to the circular electricalconnector; a memory device housed in the canister; an electricalconnection between the memory device and the circular electricalconnector, wherein the electrical connection between the memory deviceand the circular electrical connector includes a twisted pair cableemulating the electrical performance of an Universal Serial Bus cablefor the transmission of data; and means for stabilizing the memorydevice within the canister.
 16. The removable mass storage device ofclaim 15, wherein at least one of the circular electrical connector andthe backshell canister is environmentally resistant.
 17. The removablemass storage device of claim 15, wherein the circular electricalconnector is at least one of self-aligning, keyed, and scoop-proof. 18.The removable mass storage device of claim 15, wherein the external busprotocol comprises an open standard protocol.
 19. A removable massstorage device, comprising: a circular rugged electrical connectorsupporting an external bus protocol including a power signal, thecircular electrical connector including pins mechanically emulatingUniversal Serial Bus contacts; a backshell canister mated to thecircular electrical connector; a memory device housed in the canister;an electrical connection between the memory device and the circularelectrical connector; and means for stabilizing the memory device withinthe canister.
 20. The removable mass storage device of claim 19, whereinat least one of the circular electrical connector and the backshellcanister is environmentally resistant.
 21. The removable mass storagedevice of claim 19, wherein the circular electrical connector is atleast one of self-aligning, keyed, and scoop-proof.
 22. The removablemass storage device of claim 19, wherein the external bus protocolcomprises an open standard protocol.
 23. A removable mass storagedevice, comprising: a circular rugged electrical connector supporting anexternal bus protocol including a power signal, wherein the electricalconnector supports a Universal Serial Bus 2.0 protocol; a backshellcanister mated to the circular electrical connector; a memory devicehoused in the canister; an electrical connection between the memorydevice and the circular electrical connector; and means for stabilizingthe memory device within the canister.
 24. The removable mass storagedevice of claim 23, wherein at least one of the circular electricalconnector and the backshell canister is environmentally resistant. 25.The removable mass storage device of claim 23, wherein the circularelectrical connector is at least one of self-aligning, keyed, andscoop-proof.